Effect of pre-existing nuclei on crystallization during laser welding of Zr-based metallic glass
| Autor: | Hai-Lung Tsai, Yiyu Shen, Yingqi Li |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Amorphous metal Materials science Nucleation Thermodynamics Laser beam welding 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials law.invention Quality (physics) medicine.anatomical_structure law Phase (matter) Scientific method 0103 physical sciences Materials Chemistry Ceramics and Composites medicine Crystallization 0210 nano-technology Nucleus |
| Zdroj: | Journal of Non-Crystalline Solids. 513:55-63 |
| ISSN: | 0022-3093 |
| DOI: | 10.1016/j.jnoncrysol.2019.03.022 |
| Popis: | In this study, experiments are carried out to demonstrate that in laser welding of a Zr-based (Zr52.5Ti5Al10Ni14Cu17.9) bulk metallic glass (BMG), pre-existing nuclei nucleus density has significant influence on its crystallization behavior. Based on the classical nucleation/growth theory, it is concluded that a small amount of pre-existing nuclei in a BMG can shift the time-temperature-transformation (TTT) curve from a well-known ‘C-shape’ to a ‘e-shape.’ This result provides fundamental understanding on why the shape of the TTT curve for a heating process is different from that for a cooling process for the same BMG. Two quality factors were defined as a measure of the effect of pre-existing nucleus density. By integrating the classical nucleation/growth theory with the heat transfer model, the evolution of crystalline phase during laser welding for a BMG with pre-existing nuclei was studied, and the modeling predictions compared favorably with the experimental results. |
| Databáze: | OpenAIRE |
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